Lens barrel and imaging apparatus

ABSTRACT

A lens barrel includes: a plurality of lenses disposed in an outer enclosure; and an imaging device that converts image light introduced as an image capturing signal through the plurality of lenses into an image signal. The outer enclosure has a unit assembling portion in which an imaging unit is disposed. The imaging unit includes a centering lens disposed in the bottom portion of the unit assembling portion, a pressing plate that presses the centering lens from the side opposite the bottom portion, a packing disposed on the opposite side of the pressing plate, and an imaging module having the imaging device and disposed on the opposite side of the packing to the pressing plate and pressing the packing against the pressing plate. A working hole through which an adjustment jig is inserted is formed in the peripheral side portion of the unit assembling portion.

CROSS REFERENCES TO RELATED APPLICATIONS

The present invention contains subject matter related to Japanese PatentApplication JP 2007-284169 filed in the Japanese Patent Office on Oct.31, 2007, the entire contents of which being incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a technical field of a lens barrel andan imaging apparatus, and particularly to a technical field in which theposition of a centering lens is readily adjusted by using an imagingmodule to press the centering lens via a pressing plate and a packingand size reduction is achieved at the same time.

2. Description of the Related Art

Any imaging apparatus, such as a video camera and a still camera,includes a lens barrel having an imaging capability. In recent years, avariety of electronic apparatus, such as mobile phones, personalcomputers, and PDAs (Personal Digital Assistants), have been used in anincreasing number of applications, and some of such electronic apparatusinclude a built-in lens barrel. Therefore, mobile phones, personalcomputers, PDAs, and other electronic apparatus including such abuilt-in lens barrel are also used as imaging apparatus for capturingimages.

Some of such lens barrels have a configuration in which an outerenclosure houses a fixed lens, such as an objective lens, a movable unitincluding movable lenses, such as a focus lens and a zoom lens, animaging device that converts an image capturing signal acquired throughthe fixed lens and the movable lenses into an image signal, and othercomponents (see JP-A-11-311734, for example).

In a lens barrel including a movable unit, the movable unit moves in theoptical axis direction to perform, for example, a zooming operation inwhich the imaging magnification is adjusted. When the movable unit movesbetween a wide-angle end and a telescopic end, the spatial frequency ofthe entire optical system (MTF: Modulation Transfer Function) changes inaccordance with the position of the movable unit that has moved. In thelens barrel, the position of the fixed lens (centering lens) istherefore typically adjusted with respect to the optical axis so thatthe change in MTF is balanced across the range from the wide-angle endto the telescopic end.

For example, in a method for adjusting the position of the fixed lens inan image apparatus of related art, the fixed lens to be positionallyadjusted is pressed against a predetermined surface by a platespring-based pressing mechanism, and an adjustment jig is used todisplace the fixed lens in a plane perpendicular to the optical axis.

SUMMARY OF THE INVENTION

However, in the lens barrel of related art described above, in which thefixed lens to be positionally adjusted is pressed against apredetermined surface by a plate spring-based pressing mechanism, amechanism unit including the pressing mechanism and an imaging unitincluding the imaging device are spaced apart from each other.

Therefore, separate assembling spaces for independently disposing themechanism unit and the imaging unit are necessary in the outerenclosure, and the size in the optical axis direction increasesaccordingly. Such a configuration disadvantageously prevents reductionin size of the imaging apparatus.

It is desirable to provide a lens barrel and an imaging apparatus thatsolve the above problems and allow the position of the centering lens tobe readily adjusted and at the same time, the sizes of the lens barreland the imaging apparatus to be reduced.

According to an embodiment of the invention, there is provided a lensbarrel including an outer enclosure having a unit assembling portion inwhich an imaging unit is disposed, the unit assembling portion having abottom portion and a peripheral side portion protruding from theperipheral edge of the bottom portion. The imaging unit includes acentering lens disposed in the bottom portion of the unit assemblingportion in such a way that the centering lens is pressed against thebottom portion, the centering lens to be adjusted in terms of positionwith respect to the optical axis, a pressing plate that presses thecentering lens from the side opposite the bottom portion, the pressingplate having a light transmission hole through which image capturinglight passes and impinges on an imaging device, a packing disposed onthe opposite side of the pressing plate to the centering lens andpressed against the pressing plate, the packing having a transmissionhole through which the image capturing light passes and impinges on theimaging device, and an imaging module disposed on the opposite side ofthe packing to the pressing plate and pressing the packing against thepressing plate, the imaging module having the imaging device. A workinghole through which an adjustment jig is inserted is formed in theperipheral side portion of the unit assembling portion, the adjustmentjig used to adjust the position of the centering lens pressed againstthe bottom portion with respect to the optical axis.

Therefore, in the lens barrel, the centering lens is pressed against thebottom portion of the unit assembling portion by the imaging module viathe pressing plate and the packing.

In the lens barrel described above, the centering lens is glued andsecured to the unit assembling portion after the position of thecentering lens has been adjusted with respect to the optical axis. Anadhesive applying nozzle is inserted through the working hole in theunit assembling portion to apply an adhesive in the operation of gluingthe centering lens. The centering lens is secured in the unit assemblingportion by irradiating the applied adhesive with UV light.

Securing the centering lens in the unit assembling portion allowsresistance to impact to be improved and excellent opticalcharacteristics of the centering lens to be ensured.

In the lens barrel described above, to prevent ghosts from beinggenerated, the light transmission hole in the pressing plate is used asa diaphragm opening that limits the amount of the image capturing lightthat impinges on the imaging device.

In the lens barrel described above, to press the centering lensappropriately, the packing is preferably made of a rubber material.

In the lens barrel described above, a flat-plate-shaped glass plate ispreferably provided in the imaging module, the glass plate pressedagainst the packing to protect the imaging device. Providing the glassplate allows, for example, the imaging device to be protected by theglass plate and the centering lens to be pressed via the pressing plateand the packing.

In the lens barrel described above, the centering lens includes a lensportion and a flat-plate-shaped flange portion provided at the peripheryof the lens portion, and a plurality of pressing protrusions areprovided on the pressing plate, the pressing protrusions pressing theflange portion of the centering lens. Such a configuration allows thecentering lens to be pressed in a stable manner.

According to another embodiment of the invention, there is provided animaging apparatus including an outer enclosure having a unit assemblingportion in which an imaging unit is disposed, the unit assemblingportion having a bottom portion and a peripheral side portion protrudingfrom the peripheral edge of the bottom portion. The imaging unitincludes a centering lens disposed in the bottom portion of the unitassembling portion in such a way that the centering lens is pressedagainst the bottom portion, the centering lens to be adjusted in termsof position with respect to the optical axis, a pressing plate thatpresses the centering lens from the side opposite the bottom portion,the pressing plate having a light transmission hole through which imagecapturing light passes and impinges on an imaging device, a packingdisposed on the opposite side of the pressing plate to the centeringlens and pressed against the pressing plate, the packing having atransmission hole through which the image capturing light passes andimpinges on the imaging device, and an imaging module disposed on theopposite side of the packing to the pressing plate and pressing thepacking against the pressing plate, the imaging module having theimaging device. A working hole through which an adjustment jig isinserted is formed in the peripheral side portion of the unit assemblingportion, the adjustment jig used to adjust the position of the centeringlens pressed against the bottom portion with respect to the opticalaxis.

Therefore, in the imaging apparatus, the centering lens is pressedagainst the bottom portion of the unit assembling portion by the imagingmodule via the pressing plate and the packing.

A lens barrel according to one embodiment of the invention includes aplurality of lenses disposed in an outer enclosure, and an imagingdevice that converts image capturing light introduced as an imagecapturing signal through the plurality of lenses into an image signal.The outer enclosure has a unit assembling portion in which an imagingunit is disposed, the unit assembling portion having a bottom portionand a peripheral side portion protruding from the peripheral edge of thebottom portion. The imaging unit includes a centering lens disposed inthe bottom portion of the unit assembling portion in such a way that thecentering lens is pressed against the bottom portion, the centering lensto be adjusted in terms of position with respect to the optical axis, apressing plate that presses the centering lens from the side oppositethe bottom portion, the pressing plate having a light transmission holethrough which the image capturing light passes and impinges on theimaging device, a packing disposed on the opposite side of the pressingplate to the centering lens and pressed against the pressing plate, thepacking having a transmission hole through which the image capturinglight passes and impinges on the imaging device, and an imaging moduledisposed on the opposite side of the packing to the pressing plate andpressing the packing against the pressing plate, the imaging modulehaving the imaging device. A working hole through which an adjustmentjig is inserted is formed in the peripheral side portion of the unitassembling portion, the adjustment jig used to adjust the position ofthe centering lens pressed against the bottom portion with respect tothe optical axis.

Therefore, part of the imaging unit is used as a mechanism for pressingthe centering lens to carry out the centering operation instead ofindependently disposing the imaging unit and a mechanism for pressingthe centering lens spaced apart from each other. The assembling space inthe optical axis direction can be reduced accordingly. The size of thelens barrel can thus be reduced and the centering lens can be readilycentered at the same time.

Even when each component in the imaging unit shows variation inmachining and assembling accuracy, the centering lens can be centeredfor each lens barrel. Optimum characteristics of the imaging unit ineach lens barrel can therefore be ensured.

In a lens barrel according to one embodiment of the invention, thecentering lens is glued and secured to the unit assembling portion afterthe position of the centering lens has been adjusted with respect to theoptical axis. An adhesive applying nozzle is inserted through theworking hole in the unit assembling portion to apply an adhesive in theoperation of gluing the centering lens. The centering lens is secured inthe unit assembling portion by irradiating the applied adhesive with UVlight. Such a configuration can prevent the position of the centeringlens from shifting and ensure excellent optical characteristics of thecentering lens, even when an impact force is applied.

In a lens barrel according to one embodiment of the invention, the lighttransmission hole in the pressing plate is used as a diaphragm openingthat limits the amount of the image capturing light that impinges on theimaging device. Such a configuration can prevent unwanted light amongthe incident image capturing light from being incident on the imagingdevice. It is thus possible to prevent so-called ghosts, which are lightrings and balls, from being generated in an image due to repetitivelight reflection when unnecessarily intense light is incident.

In a lens barrel according to one embodiment of the invention, thepacking is made of a rubber material. Therefore, compressing the packingallows the centering lens to be pressed against the bottom portion ofthe unit assembling portion. It is thus possible to absorb variation inthe distance between the pressing plate and the glass plate and pressthe centering lens at an appropriate pressure.

In a lens barrel according to one embodiment of the invention, aflat-plate-shaped glass plate is provided in the imaging module, theglass plate pressed against the packing to protect the imaging device,whereby the number of parts can be reduced.

In a lens barrel according to one embodiment of the invention, thecentering lens includes a lens portion and a flat-plate-shaped flangeportion provided at the periphery of the lens portion, and a pluralityof pressing protrusions are provided on the pressing plate, the pressingprotrusions pressing the flange portion of the centering lens.Therefore, the centering lens is pressed at a plurality of locations onthe periphery of the lens portion, and the pressing force against thebottom portion is distributed thereacross to ensure stable pressing.

An imaging apparatus according to one embodiment of the inventionincludes a lens barrel incorporated in a housing, the lens barrelincluding a plurality of lenses disposed in an outer enclosure, and animaging device that converts image capturing light introduced as animage capturing signal through the plurality of lenses into an imagesignal. The outer enclosure has a unit assembling portion in which animaging unit is disposed, the unit assembling portion having a bottomportion and a peripheral side portion protruding from the peripheraledge of the bottom portion. The imaging unit includes a centering lensdisposed in the bottom portion of the unit assembling portion in such away that the centering lens is pressed against the bottom portion, thecentering lens to be adjusted in terms of position with respect to theoptical axis, a pressing plate that presses the centering lens from theside opposite the bottom portion, the pressing plate having a lighttransmission hole through which the image capturing light passes andimpinges on the imaging device, a packing disposed on the opposite sideof the pressing plate to the centering lens and pressed against thepressing plate, the packing having a transmission hole through which theimage capturing light passes and impinges on the imaging device, and animaging module disposed on the opposite side of the packing to thepressing plate and pressing the packing against the pressing plate, theimaging module having the imaging device. A working hole through whichan adjustment jig is inserted is formed in the peripheral side portionof the unit assembling portion, the adjustment jig used to adjust theposition of the centering lens pressed against the bottom portion withrespect to the optical axis.

Therefore, part of the imaging unit is used as a mechanism for pressingthe centering lens to carry out the centering operation instead ofindependently disposing the imaging unit and a mechanism for pressingthe centering lens spaced apart from each other. The assembling space inthe optical axis direction can be reduced accordingly. The size of thelens barrel can thus be reduced and the centering lens can be readilycentered at the same time.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1, along with FIGS. 2 to 43, shows an embodiment of the inventionand is a perspective view of an imaging apparatus;

FIG. 2 is a perspective view showing the imaging apparatus viewed from adirection different from the viewing direction in FIG. 1;

FIG. 3 is a perspective view of a lens barrel;

FIG. 4 is a perspective view showing the lens barrel viewed from adirection different from the viewing direction in FIG. 3;

FIG. 5 is a perspective exploded view of the lens barrel;

FIG. 6 is a perspective exploded, enlarged view showing an outerenclosure;

FIG. 7 is an enlarged bottom view showing an upper half portion of theouter enclosure;

FIG. 8 is an enlarged plan view showing a lower half portion of theouter enclosure;

FIG. 9 is an enlarged perspective view showing a unit assembling portionprovided in the lower half portion of the outer enclosure;

FIG. 10, along with FIGS. 11 to 13, shows how the upper half portion ofthe outer enclosure is connected to the lower half portion, and is anenlarged cross-sectional view showing a state in which engaging piecesof the upper half portion slide over engaging protrusions of the lowerhalf portion and are elastically deformed;

FIG. 11 is an enlarged cross-sectional view showing a state in which theengaging pieces elastically return to their initial shapes and theengaging protrusions are inserted into engaging holes;

FIG. 12 is an enlarged cross-sectional view showing a state in whichattachment bosses of the upper half portion are inserted into attachmentholes in the lower half portion;

FIG. 13 is an enlarged cross-sectional view showing a state in which anadhesive is applied to gaps formed between the engaging pieces and theengaging protrusions so that the upper half portion is connected to thelower half portion;

FIG. 14 is an enlarged cross-sectional view of the lens barrel;

FIG. 15 is an enlarged perspective view showing a first drive unit and afirst movable unit supported by a first guide shaft and a guiding shaft;

FIG. 16 is an enlarged perspective view of a drive motor;

FIG. 17 is an enlarged perspective view of a nut member;

FIG. 18 is an enlarged perspective view showing the configuration ofmembers disposed in the outer enclosure, part of which beingcross-sectioned, along with the outer enclosure;

FIG. 19 is an enlarged cross-sectional view of the lens barrel viewedfrom a direction different from the viewing direction in FIG. 14;

FIG. 20 is a perspective view showing the configuration of membersdisposed in the outer enclosure, part of which being cross-sectioned,along with the outer enclosure;

FIG. 21 is an enlarged perspective view of a first movable unit;

FIG. 22 is an enlarged perspective view showing the first movable unitalong with the first nut member, the first movable unit supported by thefirst guide shaft and the guiding shaft;

FIG. 23 is an enlarged plan view showing the first nut member held by anut holding portion of the first movable unit, part of which beingcross-sectioned;

FIG. 24 is an enlarged perspective view showing the first movable unitsupported by the first guide shaft and the guiding shaft with the firstnut member connected to the first movable unit;

FIG. 25, along with FIG. 26, shows the internal configuration of thelens barrel, and is an enlarged perspective view showing the state for awide-angle end;

FIG. 26 is an enlarged perspective view showing the state for atelescopic end;

FIG. 27 is an enlarged perspective view showing a lens moving member ofa second movable unit along with a second nut member, the lens movingmember supported by a second guide shaft and the guiding shaft;

FIG. 28 is an enlarged perspective view showing the lens moving memberof the second movable unit along with the second nut member joinedtherewith, the lens moving member supported by the second guide shaftand the guiding shaft;

FIG. 29, along with FIG. 30, shows the positional relationship betweenthe outer enclosure and the second movable unit, and is an enlargedcross-sectional view showing a state in which no impact force is appliedto the second movable unit;

FIG. 30 is an enlarged cross-sectional view showing a state in which animpact force is applied to the second movable unit;

FIG. 31 is an enlarged plan view showing a state in which the nut memberis held in the nut holding portion, part of which being cross-sectioned;

FIG. 32, along with FIGS. 33 and 34, explains how to drive and control asecond drive motor at the end of movement of the second movable unit,and is an enlarged cross-sectional view showing the second movable unitin action;

FIG. 33 is an enlarged cross-sectional view showing the second movableunit that has reached the end of movement;

FIG. 34 is an enlarged cross-sectional view showing the second movableunit that had reached the end of movement and the second nut member thathas then moved;

FIG. 35 is a perspective view showing the lens barrel with an imagingunit disassembled;

FIG. 36 is a perspective view showing the lens barrel with the imagingunit disassembled and viewed from a direction different from the viewingdirection in FIG. 35;

FIG. 37 is an enlarged cross-sectional view showing a state in which theimaging unit is disposed in the unit assembling portion in the lowerhalf portion;

FIG. 38 is an enlarged bottom view showing a centering lens beingcentered with respect to the optical axis;

FIG. 39 shows graphs illustrating the relationship between the amount ofdeformation of a packing and the load applied to the packing;

FIG. 40 is an enlarged rear view of the lens barrel;

FIG. 41 is an enlarged cross-sectional view of the lens barrel operatingat the wide-angle end;

FIG. 42 is an enlarged cross-sectional view of the lens barrel operatingat the telescopic end; and

FIG. 43 is a block diagram showing the overall configuration of theimaging apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The best mode for implementing a lens barrel and an imaging apparatusaccording to an embodiment of the invention will be described below withreference to the accompanying drawings.

In the best mode described below, an imaging apparatus according to anembodiment of the invention is applied to a mobile phone as an imagingapparatus, and a lens barrel according to an embodiment of the inventionis applied to a lens barrel incorporated in the mobile phone. Thecoverage of the invention is not limited to a mobile phone or a lensbarrel incorporated therein, but the invention is widely applicable to avariety of apparatus used as imaging apparatus, such as still cameras,video cameras, personal computers, PDAs (Personal Digital Assistants),and a variety of lens barrels incorporated in such a variety ofapparatus.

In the following description, the forward, backward, upward, downward,rightward, and leftward directions are those viewed by an operator ofthe imaging apparatus when the operator captures images. Therefore, thefront side becomes the subject side, and the back side becomes theoperator side.

The forward, backward, upward, downward, rightward, and leftwarddirections used in the following description are defined for ease ofdescription. The invention is not limited to these directions, but canbe implemented with any other definition.

An imaging apparatus (mobile phone) 1 includes, as shown in FIGS. 1 and2, a first housing 2 and a second housing 3 foldably connected to eachother via a hinge mechanism (not shown).

Operation keys 4, 4, . . . are arranged on one surface of the firsthousing 2. A microphone 5 is provided in the lower end portion of theone surface of the first housing 2, and audio from a user or othersources is inputted through the microphone 5.

The operation keys 4, 4, . . . include a variety of keys, such as apower on/off key 4 a for turning on and off the entire imaging apparatus1, a clear key 4 b for initializing the operation, a calling key 4 c forinitiating or terminating a call, a mode switching key 4 d for switchingamong a variety of modes, a start key 4 e for starting desiredapplication software, an imaging key 4 f for initiating or terminatingimaging, input keys for 4 g, 4 g, . . . for inputting numerals andcharacters, such as telephone numbers.

The first housing 2 is equipped with an interface connector, an earphonejack, and other terminals (not shown) as well as the operation keys 4,4, . . . and the microphone 5. The first housing 2 is further equippedwith a card slot into which a memory card, which will be describedlater, is inserted.

A display (liquid crystal display panel) 6 is disposed in one surface ofthe second housing 3. The display 6 displays a variety of information,such as a radio wave reception status, the amount of remaining batterypower, the telephone number of the other party, contents registered in atelephone book (telephone numbers, names, and other information on otherregistered parties), outgoing call histories, incoming call histories,and a variety of other registered contents.

A loudspeaker 7 is provided in the upper end portion of the secondhousing 3. The speaker 7 outputs audio and other sounds from the otherparty during a call.

The imaging apparatus 1 has a lens barrel 8, for example, incorporatedin the first housing 2 (see FIG. 2).

The lens barrel 8 has an outer enclosure 9 made of a resin material andhaving necessary portions disposed therein (see FIGS. 3 to 5).

The outer enclosure 9 has an upper half portion 10 and a lower halfportion 11 aligned in the up-down direction and connected to each other.

The upper half portion 10 has a body 12 and an assembling protrusion 13integrally formed therewith, as shown in FIG. 6. The body 12 has alaterally-elongated box shape, the lower and left sides of which beingopen, and the assembling protrusion 13 protrudes upward from the uppersurface of the body 12.

Attachment bosses 12 a, 12 a protruding downward are provided atopposite diagonal corners of the lower surface of the body 12, as shownin FIGS. 6 and 7. Engaging pieces 14, 14, 14 protrude downward from thelower edges of the body 12. The engaging pieces 14, 14, 14, each ofwhich being shaped into a substantially rectangular plate, are provided,for example, at central portions of the front edge, the rear edge, andthe right edge of the body 12. The engaging pieces 14, 14, 14 haveengaging holes 14 a, 14 a, 14 a formed therein. Each of the engagingpieces 14, 14, 14 is elastically deformable.

The outer surfaces 14 b, 14 b, 14 b of the engaging pieces 14, 14, 14are flush with the respective outer surfaces of the body 12, that is,the front surface 12 d, the rear surface 12 e, and the right sidesurface 12 f.

Guide shaft receivers 12 b, 12 b and a guiding shaft receiver 12 c, eachof which being open downward, are formed in the inner surface of theupper side portion of the body 12, as shown in FIG. 7. The guide shaftreceivers 12 b, 12 b are positioned on the left end side of the upperside portion of the body 12 and spaced apart from each other in thefront-rear direction. The guiding shaft receiver 12 c is positioned onthe right end side of the upper side portion of the body 12.

The assembling protrusion 13 is provided along the right end side of theupper side portion of the body 12, as shown in FIG. 6, and shaped into atriangular prism. The front surface 13 a of the assembling protrusion 13is seamlessly connected and flush with the front surface 12 d of thebody 12. A lens assembly hole 15 extending through the front-reardirection is formed in an area that spans the front surface 12 d and thefront surface 13 a of the upper half portion 10.

The interior of the assembling protrusion 13 communicates with theinterior of the body 12.

The lower half portion 11 includes, as shown in FIGS. 6 and 8, alaterally-elongated box-shaped body 16, the upper and left sides ofwhich being open, and a unit assembling portion 17 provided in theportion other than the left end portion of the lower end portion of thebody 16.

Attachment holes 16 a, 16 a that are open upward are formed at oppositediagonal corners of the upper surface of the body 16. Shallow insertionrecesses 16 b, 16 b, 16 b that are open outward and upward are formed inthe upper end portion of the outer surface of the body 16. The insertionrecesses 16 b, 16 b, 16 b are formed, for example, at the centralportions of the front surface 16 c, the rear surface 16 d, and the rightside surface 16 e.

Engaging protrusions 18, 18, 18 protruding outward are provided on theupper end portions of the insertion recesses 16 b, 16 b, 16 b. Theengaging protrusions 18, 18, 18, the amount of outward protrusion ofwhich increasing in lower positions, have inclined surfaces 18 a, 18 a,18 a having larger outward displacement in lower positions.

Guide shaft receivers 16 f, 16 f and a guiding shaft receiver 16 g, eachof which being open upward, are formed in the inner surface of the lowerside portion of the body 16, as shown in FIG. 8. The guide shaftreceivers 16 f, 16 f are positioned on the left end side of the lowerside portion of the body 16 and spaced apart from each other in thefront-rear direction. The guiding shaft receiver 16 g is positioned onthe right end side of the lower side portion of the body 16.

The unit assembling portion 17 has a rectangular bottom portion 19positioned on the upper side of the unit assembling portion 17 andfacing upward and downward, and a peripheral side portion 20 protrudingdownward from the periphery of the bottom portion 19, as shown in FIG.9.

A light path opening 19 a that communicates with the interior of thebody 16 is formed in the bottom portion 19 of the unit assemblingportion 17. Attachment pins 19 b, 19 b protruding downward are providedon the right and left end portions of the bottom portion 19,respectively.

Holding pins 20 a, 20 a protruding downward and spaced apart from eachother in the right-left direction are provided on the peripheral sideportion 20 of the unit assembling portion 17. Threaded holes 20 b, 20 bspaced apart from each other in the right-left direction are formed inthe lower surface of the peripheral side portion 20. Laterally-elongatedworking holes 20 c, 20 c are formed in the front and rear surfaces ofthe peripheral side portion 20. The working holes 20 c, 20 c allow theinterior of the unit assembling portion 17 to communicate with theexterior thereof.

A description will be made of how to connect the upper half portion 10to the lower half portion 11. The connection of the upper half portion10 and the lower half portion 11 is carried out after necessaryportions, such as guide shafts and guiding shafts, which will bedescribed later, have been disposed in the upper half portion 10 and thelower half portion 11.

First, the upper half portion 10 and the lower half portion 11 spacedapart in the up-down direction are brought closer to each other in theup-down direction. When the upper half portion 10 and the lower halfportion 11 are brought closer to each other, the engaging pieces 14, 14,14 of the upper half portion 10 are inserted into the insertion recesses16 b, 16 b, 16 b of the lower half portion 11, and the lower edges ofthe engaging pieces 14, 14, 14 come into contact with the engagingprotrusions 18, 18, 18.

When the upper half portion 10 and the lower half portion 11 are furtherbrought closer to each other, the engaging pieces 14, 14, 14 slide overthe inclined surfaces 18 a, 18 a, 18 a of the engaging protrusions 18,18, 18, respectively. In this process, the engaging pieces 14, 14, 14are elastically deformed outward, and the lower end portions thereof arelocated outside the insertion recesses 16 b, 16 b, 16 b (see FIG. 10).

When the upper half portion 10 and the lower half portion 11 are furtherbrought closer to each other, the lower opening edges of the engagingholes 14 a, 14 a, 14 a in the engaging pieces 14, 14, 14 are positionedto face the lower edges of the engaging protrusions 18, 18, 18,respectively. The engaging pieces 14, 14, 14 elastically return to theirinitial shapes, and the engaging protrusions 18, 18, 18 are inserted inthe engaging holes 14 a, 14 a, 14 a, respectively, as shown in FIG. 11.The attachment bosses 12 a, 12 a of the upper half portion 10 are notyet inserted into the attachment holes 16 a, 16 a in the lower halfportion 11.

In the state in which the engaging pieces 14, 14, 14 elastically returnto their initial shapes and the engaging protrusions 18, 18, 18 areinserted in the engaging holes 14 a, 14 a, 14 a, respectively, theengaging pieces 14, 14, 14 are again inserted in the insertion recesses16 b, 16 b, 16 b, respectively.

When the upper half portion 10 and the lower half portion 11 are furtherbrought closer to each other, the lower opening edges of the engagingholes 14 a, 14 a, 14 a in the engaging pieces 14, 14, 14 becomedownwardly apart from the lower edges of the engaging protrusions 18,18, 18, respectively, and at the same time, the attachment bosses 12 a,12 a are inserted into the attachment holes 16 a, 16 a.

When the upper half portion 10 and the lower half portion 11 are furtherbrought closer to each other, the lower surface of the upper halfportion 10 comes into contact with the upper surface of the lower halfportion 11 (see FIG. 12). With the lower surface of the upper halfportion 10 in contact with the upper surface of the lower half portion11, gaps 21, 21, 21 are formed between the lower opening edges of theengaging holes 14 a, 14 a, 14 a in the engaging pieces 14, 14, 14 andthe lower edges of the engaging protrusions 18, 18, 18.

Finally, adhesive 22, 22, 22 are applied to the gaps 21, 21, 21. Theconnection of the upper half portion 10 to the lower half portion 11 isthus completed (see FIG. 13). Applying the adhesive 22, 22, 22 to thegaps 21, 21, 21 is carried out by using a jig (not shown) to hold theouter enclosure 9.

With the upper half portion 10 connected to the lower half portion 11,the entire engaging pieces 14, 14, 14 are inserted in the insertionrecesses 16 b, 16 b, 16 b, and the outer surfaces of the engaging pieces14, 14, 14 do not protrude outward from the outermost surface of thelower half portion 11 (see FIG. 13). The size of the lens barrel 8 canthus be reduced.

As described above, with the upper half portion 10 connected to thelower half portion 11, the adhesive 22, 22, 22 are applied to the gap21, 21, 21 formed between the lower opening edges of the engaging holes14 a, 14 a, 14 a and the lower edges of the engaging protrusions 18, 18,18, respectively. Therefore, when a force acts in such a way that theupper half portion 10 and the lower half portion 11 disengage from eachother, that is, the upper half portion 10 is moved upward and the lowerhalf portion 11 is moved downward, the adhesive 22, 22, 22 restrict theupward movement of the upper half portion 10 and the downward movementof the lower half portion 11.

Therefore, applying the adhesive 22, 22, 22 to the gap 21, 21, 21ensures strong connection between the upper half portion 10 and thelower half portion 11. Even when an impact force is applied to theimaging apparatus 1, for example, when it falls, the upper half portion10 and the lower half portion 11 will not disengage from each other butmaintain their connected state.

An example of the adhesive 22, 22, 22 is an UV curable adhesive. Toprevent the adhesive 22, 22, 22 from flowing inside the outer enclosure9 when they are applied to the gap 21, 21, 21, it is preferable toselect an adhesive having a viscosity that prevents the adhesive fromflowing inside the outer enclosure 9.

It is however noted that in the lens barrel 8, the adhesive 22, 22, 22are applied only to the gap 21, 21, 21 formed on the outer surface sideof the lower half portion 11, and no adhesive is applied between thelower surface of the upper half portion 10 and the upper surface of thelower half portion 11. The adhesive therefore unlikely flows inside theouter enclosure 9.

The above description has been made with reference to the case where theupper half portion 10 has the elastically deformable engaging pieces 14,14, 14 and the lower half portion 11 has the engaging protrusions 18,18, 18. Conversely, the upper half portion may have engaging protrusionsand the lower half portion may have elastically deformable engagingpieces for the connection between the upper half portion and the lowerhalf portion.

A first drive unit 23 and a second drive unit 24, spaced apart from eachother in the up-down direction, are attached to the left end portion ofthe outer enclosure 9 (see FIG. 14).

The first drive unit 23 is attached to the upper half portion 10 of theouter enclosure 9, as shown in FIGS. 14 and 15. The first drive unit 23includes a first support sheet metal 25, a first lead screw 26 rotatablysupported by the first support sheet metal 25, a first drive motor 27attached to the first support sheet metal 25, and a first nut member 28that threadably engages the first lead screw 26.

The first support sheet metal 25 is formed of a base portion 25 aextending in the up-down direction and support portions 25 b, 25 cprotruding rightward from the upper and lower ends of the base portion25 a.

The first lead screw 26, the axial direction of which is oriented in theup-down direction, is rotatably supported by the support portions 25 b,25 c of the first support sheet metal 25.

The first drive motor 27 is attached to the upper surface of the uppersupport portion 25 b. The first lead screw 26 is provided as the drivemotor shaft of the first drive motor 27, and rotated when the firstdrive motor 27 is driven. A plate spring 27 a that urges the first leadscrew 26 from the rear side toward the front end side is provided on therear side of the first drive motor 27, as shown in FIG. 16 (The platespring 27 a is only shown in FIG. 16 but not in the other drawings.)

The first nut member 28 is made of a thick metal material, and includesan annular supported portion 29 and a restricted portion 30 radiallyprotruding from the supported portion 29, as shown in FIG. 17. The twoside surfaces of the restricted portion 30 are formed as restrictedsurfaces 30 a, 30 a parallel to each other. The first lead screw 26,when inserted into the supported portion 29, threadably engages thefirst nut member 28.

The first drive unit 23 is attached to the upper half portion 10 byinserting the first drive unit 23, excluding part thereof, into anopening 10 a located on the left side of the upper half portion 10 andsecuring the base portion 25 a of the first support sheet metal 25, forexample, using screws, as shown in FIG. 14. With the first drive unit 23attached to the upper half portion 10, the base portion 25 a of thefirst support sheet metal 25 blocks the opening 10 a located on the leftside of the upper half portion 10, and the support portion 25 b of thefirst support sheet metal 25 and the first drive motor 27 are disposedon an upper surface 12 g of the body 12 of the upper half portion 10.

The second drive unit 24 is attached to the lower half portion 11 of theouter enclosure 9, as shown in FIGS. 14 and 18. The second drive unit 24includes a second support sheet metal 31, a second lead screw 32rotatably supported by the second support sheet metal 31, a second drivemotor 33 attached to the second support sheet metal 31, and a second nutmember 34 that threadably engages the second lead screw 32.

The second support sheet metal 31 is formed of a base portion 31 aextending in the up-down direction and support portions 31 b, 31 cprotruding rightward from the upper and lower ends of the base portion31 a.

The second lead screw 32, the axial direction of which is oriented inthe up-down direction, is rotatably supported by the support portions 31b, 31 c of the second support sheet metal 31.

The second drive motor 33 is attached to the lower surface of the lowersupport portion 31 c. The second lead screw 32 is provided as the drivemotor shaft of the second drive motor 33, and is rotated when the seconddrive motor 33 is driven. A plate spring 33 a that urges the second leadscrew 32 from the rear side toward the front end side is provided on therear side of the second drive motor 33, as shown in FIG. 16 (The platespring 33 a is only shown in FIG. 16 but not in the other drawings.)

The second nut member 34 is made of a thick metal material, and includesan annular supported portion 35 and a restricted portion 36 radiallyprotruding from the supported portion 35, as shown in FIG. 17. The twoside surfaces of the restricted portion 36 are formed as restrictedsurfaces 36 a, 36 a parallel to each other. The second lead screw 32,when inserted into the supported portion 35, threadably engages thesecond nut member 34.

The second drive unit 24 is attached to the lower half portion 11 byinserting the second drive unit 24, excluding part thereof, into anopening 11 a located on the left side of the lower half portion 11 andsecuring the base portion 31 a of the second support sheet metal 31, forexample, using screws, as shown in FIG. 14. With the second drive unit24 attached to the lower half portion 11, the base portion 31 a of thesecond support sheet metal 31 blocks the opening 11 a located on theleft side of the lower half portion 11, and the support portion 31 b ofthe second support sheet metal 31 and the second drive motor 33 aredisposed on the lower surface 16 h of the body 16 of the lower halfportion 11.

As described above, the first drive motor 27 is disposed on the uppersurface 12 g of the body 12 of the upper half portion 10, and the seconddrive motor 33 is disposed on the lower surface 16 h of the body 16 ofthe lower half portion 11. In this state, as shown in FIG. 14, the uppersurface U1 of the first drive motor 27 does not protrude upward from theupper surface U2 of the assembling protrusion 13 of the upper halfportion 10, and the lower surface D1 of the second drive motor 33 doesnot protrude downward from the lower surface D2 of a circuit substrate,which will be described later, attached to the lower side of the unitassembling portion 17 of the lower half portion 11.

Therefore, the first drive motor 27 is disposed at a level lower thanthe upper surface U2 of the assembling protrusion 13 located at theuppermost level in the outer enclosure 9, and the second drive motor 33is disposed at a level higher than the portion D2 located at thelowermost level among the members attached to the outer enclosure 9.Such a configuration allows reduction in size of the lens barrel 8.

In the state in which the first drive unit 23 is attached to the upperhalf portion 10 and the second drive unit 24 is attached to the lowerhalf portion 11, and the upper half portion 10 is connected to the lowerhalf portion 11 to form the outer enclosure 9, the central axis M1 ofthe first lead screw 26 is aligned with the central axis M2 of thesecond lead screw 32, as shown in FIG. 14.

An objective lens 37 is disposed in the lens assembly hole 15 in theassembling protrusion 13 of the upper half portion 10 (see FIGS. 5 and19). The objective lens 37, the optical axis P1 of which is oriented inthe front-rear direction, serves to collect image capturing lightintroduced when a subject is imaged.

A prism 38 is disposed behind the objective lens 37 in the upper halfportion 10. The prism 38 serves to bend the image capturing lightintroduced through the objective lens 37 and guide it downward.

A first fixed lens 39 is disposed under the prism 38 in the upper halfportion 10.

A first guide shaft 40, a second guide shaft 41, and a guiding shaft 42,each of which extends in the up-down direction, are disposed in theouter enclosure 9 (see FIGS. 5, 14, 18, 19, and 20).

The first guide shaft 40 and the second guide shaft 41 are disposed inthe left end portion of the outer enclosure 9, and both axial ends ofthese guide shafts are held in the guide shaft receivers 12 b, 12 b inthe upper half portion 10 and the guide shaft receivers 16 f, 16 f inthe lower half portion 11, respectively. The first guide shaft 40 andthe second guide shaft 41 are therefore disposed in such a way that theyare spaced apart from each other in the front-rear direction.

The guiding shaft 42 is disposed in the right end portion of the outerenclosure 9, and both axial ends are held in the guiding shaft receiver12 c in the upper half portion 10 and the guiding shaft receiver 16 g inthe lower half portion 11, respectively.

A first movable unit 43 is slidably supported by the first guide shaft40 and the guiding shaft 42 (see FIGS. 14 and 15). The first movableunit 43 includes a focus lens 44 and a first lens holder 45 that holdsthe focus lens 44.

The first lens holder 45 is obtained by molding a resin material tointegrally form a lens holding portion 46 that holds the focus lens 44,a shaft receiver 47 provided to the left of the lens holding portion 46,and a nut holding portion 48 provided to the left of the lens holdingportion 46 and in front of the shaft receiver 47, as shown in FIGS. 21and 22.

The lens holding portion 46 is shaped into a substantially flat plate. Ashaft receiving groove 46 a that is open rightward is formed by cuttingthe right end of the lens holding portion 46. A detection protrusion 46b protruding upward is provided at the right end of the lens holdingportion 46.

The shaft receiver 47 has a substantially tubular shape elongated in theup-down direction.

The nut holding portion 48 includes a base portion 49 facing upward anddownward, standing walls 50, 50 protruding upward from the front andrear ends of the base portion 49, a connecting portion 51 that connectsthe upper surface of one of the standing walls 50 to the upper surfaceof the other standing wall 50, and protrusions 52, 52 protrudingleftward from the front and rear ends of the base portion 49.

The base portion 49 becomes wider in the front-rear direction inpositions closer to its left end. In the base portion 49, the uppersurface of the left end portion in the central part in the front-reardirection is a first guiding surface 49 a inclined downward in theleftward direction.

Facing surfaces in the right half of the standing walls 50, 50 areformed as restricting surfaces 50 a, 50 a parallel to each other. Thestanding walls 50, 50 have second guiding surfaces 50 b, 50 b connectedto the left edges of the restricting surfaces 50 a, 50 a and inclined indirections the distance between the second guiding surfaces 50 b, 50 bincreases.

A stopper protrusion 51 a is provided on the upper surface of theconnecting portion 51.

The upper surfaces of the left end portions of the protrusions 52, 52are third guiding surfaces 52 a, 52 a inclined downward in the leftwarddirection. Receiving surfaces 52 b, 52 b slightly protruding upward areprovided immediately to the right of the third guiding surfaces 52 a, 52a of the protrusions 52, 52.

The shaft receiver 47 is supported by the first guide shaft 40, and theshaft receiving groove 46 a formed in the lens holding portion 46 issupported by the guiding shaft 42, whereby the first lens holder 45 canbe moved in the up-down direction.

The first nut member 28 is inserted into the nut holding portion 48 andheld therein (see FIGS. 22 to 24). The restricted portion 30 of thefirst nut member 28 is inserted from left between the standing walls 50,50. The first nut member 28 is thus held by the nut holding portion 48.

To hold the first nut member 28 by the nut holding portion 48, therestricted portion 30 and the supported portion 29 are first guided inthe up-down direction by the first guiding surface 49 a of the baseportion 49 and the third guiding surfaces 52 a, 52 a of the protrusions52, 52, respectively, and then the restricted portion 30 is guided inthe front-rear direction by the second guiding surfaces 50 b, 50 b ofthe standing walls 50, 50. The restricted portion 30 is thus insertedbetween the standing walls 50, 50.

Since the first nut member 28 is guided by the first guiding surface 49a, the second guiding surfaces 50 b, 50 b, and the third guidingsurfaces 52 a, 52 a to insert the restricted portion 30 between thestanding walls 50, 50 as described above, the restricted portion 30 canbe reliably and readily inserted between the standing walls 50, 50.

A second movable unit 53 is slidably supported by the second guide shaft41 and the guiding shaft 42 (see FIGS. 14, 25, and 26). The secondmovable unit 53 includes a lens moving member 54 and a joining member 55joined therewith.

The lens moving member 54 includes a zoom lens 56 and a second lensholder 57 that holds the zoom lens 56 (see FIG. 27).

The second lens holder 57 is obtained by molding a resin material tointegrally form a lens holding portion 58 that holds the zoom lens 56, ashaft receiver 60 provided to the left of the lens holding portion 58,and a nut holding portion 61 provided to the left of the lens holdingportion 58.

The lens holding portion 58 is formed of a substantially flatplate-shaped holding plane portion 58 a and a holding tubular portion 58b protruding downward from part of the holding plane portion 58 a. Ashaft receiving groove 58 c that is open rightward is formed by cuttingthe right end of the holding plane portion 58 a. A detection protrusion58 d protruding downward is provided at the right end of the lensholding portion 58.

Engaging portion 59, 59, . . . protruding outward are provided on thefront and rear sides of the holding plane portion 58 a of the lensholding portion 58. The engaging portion 59, 59, . . . , the amount ofoutward protrusion of which increasing in upper positions, have inclinedsurfaces 59 a, 59 a, . . . having larger outward displacement in upperpositions. The upper surfaces of the engaging portion 59, 59, . . . areformed as locking surfaces 59 b, 59 b, . . . .

The shaft receiver 60 has a substantially tubular shape elongated in theup-down direction.

The nut holding portion 61 includes a base portion 62 facing upward anddownward, standing walls 63, 63 protruding downward from the front andrear ends of the base portion 62, a connecting portion 64 that connectsthe lower surface of one of the standing walls 63 to the lower surfaceof the other standing wall 63, and protrusions 65, 65 protrudingleftward from the front and rear ends of the base portion 62.

The base portion 62 becomes wider in the front-rear direction inpositions closer to the left end. In the base portion 62, the lowersurface of the left end portion in the central part in the front-reardirection is a first guiding surface 62 a inclined upward in theleftward direction.

Facing surfaces in the right half of the standing walls 63, 63 areformed as restricting surfaces 63 a, 63 a parallel to each other. Thestanding walls 63, 63 have second guiding surfaces 63 b, 63 b connectedto the left edges of the restricting surfaces 63 a, 63 a and inclined indirections the distance between the second guiding surfaces 63 b, 63 bincreases.

Stopper protrusions 64 a, 64 a spaced apart from each other in thefront-rear direction are provided on the lower surface of the connectingportion 64.

The lower surfaces of the left end portions of the protrusions 65, 65are third guiding surfaces 64 a, 64 a inclined upward in the leftwarddirection. Receiving surfaces 65 b, 65 b slightly protruding downwardare provided immediately to the right of the third guiding surfaces 65a, 65 a of the protrusions 65, 65.

The shaft receiver 60 is supported by the second guide shaft 41, and theshaft receiving groove 58 c formed in the lens holding portion 58 issupported by the guiding shaft 42, whereby the second lens holder 57 canbe moved in the up-down direction.

The second nut member 34 is inserted into the nut holding portion 61 andheld therein (see FIGS. 27 and 28). The restricted portion 36 of thesecond nut member 34 is inserted from left between the standing walls63, 63. The second nut member 34 is thus held by the nut holding portion61.

To hold the second nut member 34 by the nut holding portion 61, therestricted portion 36 and the supported portion 35 are first guided inthe up-down direction by the first guiding surface 62 a of the baseportion 62 and the third guiding surfaces 65 a, 65 a of the protrusions65, 65, respectively, and then the restricted portion 36 is guided inthe front-rear direction by the second guiding surfaces 63 b, 63 b ofthe standing walls 63, 63. The restricted portion 36 is thus insertedbetween the standing walls 63, 63.

Since the second nut member 34 is guided by the first guiding surface 62a, the second guiding surfaces 63 b, 63 b, and the third guidingsurfaces 65 a, 65 a to insert the restricted portion 36 between thestanding walls 63, 63 as described above, the restricted portion 36 canbe reliably and readily inserted between the standing walls 63, 63.

The joining member 55 is, for example, a shutter or diaphragm devicethat controls the amount of light.

The joining member 55 includes a support case 66, wing members 67, 67,67 openably and closably supported by the lower surface of the supportcase 66, and a sheet member 68 that presses the wing members 67, 67, 67from below, as shown in FIG. 14. The sheet member 68 has a diaphragmopening 68 a having a predetermined size. Therefore, the sheet member 68serves as a diaphragm member that controls the amount of light passingthrough the opening formed by the wing members 67, 67, 67 when the wingmembers 67, 67, 67 are fully open.

The support case 66 includes a lower wall 69 facing upward and downwardand joining portions 70, 70, . . . protruding upward from the peripheryof the lower wall 69, as shown in FIGS. 25 and 26. Each of the joiningportions 70, 70, . . . is formed into a substantially rectangular plate,and has a locking hole 70 a at a position close to the upper edge. Thejoining portions 70, 70, . . . are elastically deformable.

A description will be made of how to join the joining member 55 with thelens moving member 54.

First, the lens moving member 54 and the joining member 55 spaced apartin the up-down direction are brought closer to each other. When thejoining member 55 is brought closer to the lens moving member 54, theupper edges of the joining portions 70, 70, . . . of the joining member55 come into contact with the engaging portions 59, 59, . . . .

When the joining member 55 is further brought closer to the lens movingmember 54, the joining portions 70, 70, . . . slide over the inclinedsurfaces 59 a, 59 a . . . of the engaging portions 59, 59, . . . ,respectively. In this process, the joining portions 70, 70, . . . areelastically deformed outward.

When the joining member 55 is further brought closer to the lens movingmember 54, the upper opening edges of the locking holes 70 a, 70 a . . .in the joining portions 70, 70, . . . are positioned to face the upperedges of the engaging portions 59, 59, . . . , respectively. The joiningportions 70, 70, . . . elastically return to their initial shapes, andthe engaging portions 59, 59, . . . are inserted in the locking holes 70a, 70 a, . . . , respectively.

When the joining portions 70, 70, . . . elastically return to theirinitial shapes, and the engaging portions 59, 59, . . . are inserted inthe locking holes 70 a, 70 a, . . . , respectively, the upper openingedges of the locking holes 70 a, 70 a, . . . are locked on the lockingsurfaces 59 b, 59 b, . . . of the engaging portions 59, 59, . . . . Thejoining member 55 is thus joined with the lens moving member 54.

As described above, in the state in which the joining member 55 isjoined with the lens moving member 54 to form the second movable unit53, the amount of joint between the joining portion 70 and the engagingportion 59 is the amount of joint A in the thickness direction, as shownin FIG. 29.

The second movable unit 53 is movably supported in the up-down directionby the second guide shaft 41 and the guiding shaft 42 in the outerenclosure 9, and moved along the inner surface 9 a of the outerenclosure 9 in the up-down direction. The distance between the innersurface 9 a of the outer enclosure 9 and the engaging portions 59, 59, .. . or the joining portions 70, 70, . . . is a distance B (see FIG. 29),which is smaller than the amount of joint A described above.

Therefore, when a large impact force is applied to the imaging apparatus1, for example, when it falls, and the joining portions 70, 70, . . .are elastically deformed in the direction in which they disengage fromthe engaging portions 59, 59, . . . , the deformation of the joiningportions 70, 70, . . . is restricted by the inner surface 9 a of theouter enclosure 9, as shown in FIG. 30, which prevents the joiningportions 70, 70, . . . from disengaging from the engaging portions 59,59, . . . .

Therefore, even when elastic deformation is used to join the joiningmember 55 with the lens moving member 54 so as to form the secondmovable unit 53, no impact will cause the joining member 55 to drop fromthe lens moving member 54. It is therefore possible to prevent thejoining member 55, when an impact is applied, from dropping off the lensmoving member 54 by using a simple, elastic deformation-based method forjoining the joining member 55 with the lens moving member 54 withoutusing a costly method, such as bonding, for joining the joining member55 with the lens moving member 54.

Further, in the lens barrel 8, since the joining member 55 includes thewing members 67, 67, 67 that serve as a shutter or diaphragm device thatcontrols the amount of introduced light, the shutter or diaphragm deviceis moved integrally with the lens moving member 54 that is moved in theoptical axis direction, so that the positional relationship between thelens moving member 54 and the shutter or diaphragm device remainsunchanged. The shutter or diaphragm device can thus readily control theamount of light.

Further, since the joining member 55 includes the sheet member 68 thatserves as a diaphragm member, the diaphragm member can be disposed inthe vicinity of the shutter or diaphragm device. It is thus possible toprevent mismatch in conversion characteristic between the inherentbrightness of an image and the signal of the image (shading) resultingfrom the shutter or diaphragm device.

In addition, since the diaphragm member is disposed in the vicinity ofthe shutter device, so that the wing members 67, 67, 67 are located at aposition where the diameter of the introduced image capturing light beamis small, the amount of movement of the wing members 67, 67, 67 can besmall and the shutter can operate at a higher speed.

The above description has been made with reference to the case where thelens moving member 54 has the engaging portions 59, 59, . . . and thejoining member 55 has the elastically deformable joining portions 70,70, . . . . Conversely, the lens moving member may have elasticallydeformable joining portions and the joining member may have engagingportions to join the joining member with the lens moving member.

As described above, the first movable unit 43 is movably supported inthe up-down direction by the first guide shaft 40 and the guiding shaft42, and the second movable unit 53 is movably supported in the up-downdirection by the second guide shaft 41 and the guiding shaft 42.

The first movable unit 43 and the second movable unit 53 are connectedto the first nut member 28 and the second nut member 34, respectively.When the first drive motor 27 is driven to rotate the first lead screw26, the first nut member 28 is moved in the direction according to therotational direction of the first lead screw 26, and the first movableunit 43 is moved in the up-down direction. When the second drive motor33 is driven to rotate the second lead screw 32, the second nut member34 is moved in the direction according to the rotational direction ofthe second lead screw 32, and the second movable unit 53 is moved in theup-down direction.

The first guide shaft 40 supports an urging spring 71, which is acompression spring, and the second guide shaft 41 supports an urgingspring 72, which is a compression spring (see FIGS. 25 and 26).

The urging spring 71 is compressed in such a way that one end is incontact with the lower surface of the shaft receiver 47 of the firstlens holder 45 in the first movable unit 43 and the other end is incontact with the inner surface of the lower side portion of the lowerhalf portion 11. The first movable unit 43 is thus urged upward.

Therefore, the urging force of the urging spring 71 urges the first lensholder 45 upward, and the receiving surfaces 52 b, 52 b provided on theprotrusions 52, 52 of the nut holding portion 48 are pressed against thesupported portion 29 of the first nut member 28 from below.

The urging spring 72 is compressed in such a way that one end is incontact with the upper surface of the shaft receiver 60 of the secondlens holder 57 in the second movable unit 53 and the other end is incontact with the inner surface of the upper side portion of the upperhalf portion 10. The second movable unit 53 is thus urged downward.

Therefore, the urging force of the urging spring 72 urges the secondlens holder 57 downward, and the receiving surfaces 65 b, 65 b providedon the protrusions 65, 65 of the nut holding portion 61 are pressedagainst the supported portion 35 of the second nut member 34 from above.

As described above, since the receiving surfaces 52 b, 52 b of the firstlens holder 45 urged by the urging force of the urging spring 71 arepressed against the first nut member 28, and the receiving surfaces 65b, 65 b of the second lens holder 57 urged by the urging force of theurging spring 72 are pressed against the second nut member 34, therewill be no axial (up-down direction) backlash between the supportedportion 29 of the first nut member 28 and the first lead screw 26 or noaxial (up-down direction) backlash between the supported portion 35 ofthe second nut member 34 and the second lead screw 32.

Further, as described above, the first nut member 28 and the second nutmember 34 are held by the nut holding portion 48 of the first lensholder 45 and the nut holding portion 61 of the second lens holder 57,respectively. As will be described below, there will be no backlash inthe direction perpendicular to the axial direction between the supportedportion 29 of the first nut member 28 and the first lead screw 26 or nobacklash in the direction perpendicular to the axial direction betweenthe supported portion 35 of the second nut member 34 and the second leadscrew 32.

Preventing backlash for the first nut member 28 is carried out in thesame manner as for the second nut member 34. Therefore, a descriptionwill be only made of how to prevent backlash for the first nut member 28by way of example, and no description will be made of how to preventbacklash for the second nut member 34.

As shown in FIG. 31, the restricted portion 30 of the first nut member28 is inserted between the standing walls 50, 50 of the nut holdingportion 48, and the restricted surfaces 30 a, 30 a of the first nutmember 28 come into contact with the restricting surfaces 50 a, 50 a,respectively, whereby the first nut member 28 is restricted fromrotating in the direction R. A slight clearance C (the clearance C isexaggerated in FIG. 31) is present between the restricted surfaces 30 a,30 a and the restricting surfaces 50 a, 50 a to tolerate machining errorof the first nut member 28 and the standing walls 50, 50 and ensuresmooth insertability of the first nut member 28 between the standingwalls 50, 50. Therefore, the clearance C may cause the first nut member28 to slightly rotate with reference to the contact point S where therestricted surface 30 a come into contact with the restricting surface50 a in the direction R, that is, the direction substantiallyperpendicular to the axial direction of the first lead screw 26. In FIG.31, the solid line indicates the state in which the first nut member 28has been rotated in the direction R, and the broken line indicates thestate in which the first nut member 28 is yet to rotate in the directionR.

When the first nut member 28 rotates in the direction R, the first nutmember 28 is inclined by an angle α with reference to the contact pointS in the direction substantially perpendicular to the axial direction ofthe first lead screw 26. The inclination does not occur with referenceto the supported portion 29 that threadably engages the first lead screw26 but occurs with reference to the contact point S on the restrictedportion 30 radially protruding from the supported portion 29. Therefore,the inclination occurs with reference to the restricted portion 30located far away from the supported portion 29 that threadably engagesthe first lead screw 26, and hence the amount of displacement H of thecenter P of the supported portion 29 is significantly small when thesupported portion 29 is inclined by an angle α.

As described above, the first nut member 28 has the restricted portion30 radially protruding from the supported portion 29 that threadablyengages the first lead screw 26, and the restricted surfaces 30 a, 30 aof the restricted portion 30 radially protruding from the supportedportion 29 are in contact with the restricting surfaces 50 a, 50 a ofthe standing walls 50, 50, so that the first nut member 28 is restrictedfrom rotating in the direction R. The first nut member 28 is thereforedisplaced with respect to the first lead screw 26 only by a very smallamount. It is thus possible to prevent backlash between the supportedportion 29 of the first nut member 28 and the first lead screw 26 in thedirection perpendicular to the axial direction of the first lead screw26.

As described above, since the second nut member 34 has the sameconfiguration as that of the first nut member 28, no backlash willoccur, in the second nut member 34 as well, between the supportedportion 35 and the second lead screw 32 in the direction perpendicularto the axial direction of the second lead screw 32.

Position detection sensors 73, 73 are disposed in the outer enclosure 9and spaced apart from each other in the up-down direction (see FIGS. 25and 26). An example of the position detection sensor 73 is aphoto-interrupter. Each of the position detection sensors 73, 73 has aslit 73 a.

When the first movable unit 43 or the second movable unit 53 moves andthe detection protrusion 46 b provided on the first lens holder 45 inthe first movable unit 43 or the detection protrusion 58 d provided onthe second lens holder 57 in the second movable unit 53 passes throughthe corresponding slit 73 a, the corresponding position detection sensor73 detects the position of the first movable unit 43 or the secondmovable unit 53.

In the lens barrel 8, the first drive motor 27 and the second drivemotor 33 are driven and controlled at the ends of movement of the firstmovable unit 43 and the second movable unit 53 in the following mannerbased on the result of the detection operation in which the positiondetection sensors 73, 73 detect the positions of the first movable unit43 and the second movable unit 53.

Driving and controlling the first drive motor 27 is carried out in thesame manner as driving and controlling the second drive motor 33.Therefore, a description will be only made of how to drive and controlthe second drive motor 33 by way of example (see FIGS. 32 to 34), and nodescription will be made of how to drive and control the first drivemotor 27.

In the lens barrel 8, energizing and deenergizing the lens barrel 8allows switching between a drive mode in which an image can be capturedand a non-drive mode in which no image can be captured. The switchingbetween the drive mode and the non-drive mode can be performed byoperating the imaging key 4f disposed on the first housing 2 of theimaging apparatus 1.

In the non-drive mode, the first movable unit 43 is moved to the upperend of movement, and the second movable unit 53 is moved to the lowerend of movement (see FIG. 14).

Restricting portions 11 b, 11 b protruding upward are provided on theinner surface of the lower side portion of the lower half portion 11 ofthe outer enclosure 9 (see FIG. 32). Similarly, restricting portionsprotruding downward (not shown) are provided on the inner surface of theupper side portion of the upper half portion 10.

The second movable unit 53 stops moving at the lower end of movementwhen the stopper protrusions 64 a, 64 a provided on the connectingportion 64 of the second lens holder 57 come into contact with therestricting portions 11 b, 11 b (non-drive mode). The movement of thesecond movable unit 53 is stopped at the lower end of movement by usingthe position detection sensor 73 to detect the position of the secondmovable unit 53, and sending a stop signal to the second drive motor 33based on the detection result to stop the rotation of the second drivemotor 33.

As described above, the second movable unit 53 moves under the followingconditions: The urging force of the urging spring 72 supported by thesecond guide shaft 41 urges the second lens holder 57 downward, so thatthe receiving surfaces 65 b, 65 b provided on the protrusions 65, 65 ofthe nut holding portion 61 are pressed against the supported portion 35of the second nut member 34 from above (see FIG. 32).

In the state in which the second nut member 34 is held by the nutholding portion 61 and the receiving surfaces 65 b, 65 b are pressedagainst the supported portion 35 from above, a predetermined gap L isformed between the lower surface of the restricted portion 36 and theupper surface of the connecting portion 64 of the nut holding portion61. The size of the gap L, for example, ranges from 0.3 to 0.4 mm.

When the second movable unit is moved downward and the positiondetection sensor 73 detects the position of the second movable unit 53,the second movable unit 53 stops moving at the lower end of movementwhen the stopper protrusions 64 a, 64 a provided on the connectingportion 64 of the second lens holder 57 come into contact with therestricting portions 11 b, 11 b (see FIG. 33).

A stop signal is then sent to the second drive motor 33. Specifically,the stop signal is still sent to the second drive motor 33 even afterthe second movable unit 53 stops at the end of movement until the secondlead screw 32 rotates by a predetermined amount. Therefore, even afterthe stopper protrusions 64 a, 64 a come into contact with therestricting portions 11 b, 11 b and the second movable unit 53 stops atthe lower end of movement, the second lead screw 32 rotates by apredetermined amount.

When the second movable unit 53 stops at the lower end of movement andthen the second lead screw 32 rotates by a predetermined amount, thesecond movable unit 53 does not move downward anymore because it stopsat the end of movement, whereas the second nut member 34 is moveddownward by the rotation of the second lead screw 32 until the secondlead screw 32 stops rotating and then held at the holding position inthe non-drive mode (see FIG. 34).

Therefore, the second nut member 34 disengages from the receivingsurfaces 65 b, 65 b of the nut holding portion 61, and a predeterminedgap T is formed between the second nut member 34 and the receivingsurfaces 65 b, 65 b. The size of the gap T, for example, ranges from0.05 to 0.1 mm.

As described above, in the lens barrel 8, in the non-drive mode, thesecond nut member 34 disengages from the receiving surfaces 65 b, 65 bof the nut holding portion 61, and, a predetermined gap T is formedbetween the second nut member 34 and the receiving surfaces 65 b, 65 b.

Therefore, in the non-drive mode, when a large impact force is appliedto the second movable unit 53, for example, when the imaging apparatus 1falls, the impact force is unlikely transmitted from the second lensholder 57 to the second nut member 34, and hence the impact force isunlikely applied to the second drive motor 32. It is therefore possibleto prevent the second drive motor 32 from malfunctioning.

As described above, the first movable unit 43 and the first nut member28 have a configuration similar to that of the second movable unit 53and the second nut member 34. Therefore, when a large impact force isapplied to the first movable unit 43, the impact fore is unlikelytransmitted from the first lens holder 45 to the first nut member 28,and hence the impact force is unlikely applied to the first drive motor27. It is therefore possible to prevent the first drive motor 27 frommalfunctioning.

Further, since the second lead screw 32 rotates to move the second nutmember 34 downward after the second movable unit 53 stops at the end ofmovement, the second nut member 34 reliably disengages from thereceiving surfaces 65 b, 65 b of the nut holding portion 61.

When the lens barrel 8 is energized and the non-drive mode is set, thesecond nut member 34 is moved upward to the point where it comes intocontact with the receiving surfaces 65 b, 65 b of the nut holdingportion 61 (see FIG. 33), and the first nut member 28 is moved downwardto the point where it comes into contact with the receiving surfaces 52b, 52 b of the nut holding portion 48.

Therefore, the position where the first movable unit 43 and the secondmovable unit 53 start moving in the drive mode is the position where thesecond nut member 34 abuts the receiving surfaces 65 b, 65 b of the nutholding portion 61 and the first nut member 28 abuts the receivingsurfaces 52 b, 52 b of the nut holding portion 48.

The above movement start positions of the first nut member 28 and thesecond nut member 34 are apart from the receiving surfaces 65 b, 65 band the receiving surfaces 52 b, 52 b, respectively, but close to thepositions where the first nut member 28 and the second nut member 34 areheld in the non-drive mode. Therefore, when the non-drive mode isswitched to the drive mode, the first nut member 28 and the second nutmember 34 are moved by a small distance from the positions where theyare held to the positions where they start moving.

Therefore, since the amounts of movement of the first movable unit 43and the second movable unit 53 are small when the non-drive mode isswitched to the drive mode, it is possible to reduce the time necessaryto start operation when the non-drive mode is switched to the drivemode.

An imaging unit 74 is disposed in the unit assembling portion 17 of thelower half portion 11 of the outer enclosure 9 (see FIG. 14). Theimaging unit 74 includes a centering lens 75, a pressing plate 76, apacking 77, and an imaging module 78 disposed in this order from above,as shown in FIGS. 35 and 36.

The centering lens 75 is provided as a second fixed lens and formed of alens portion 75 a and a flat-plate-shaped flange portion 75 b disposedat the periphery of the lens portion 75 a. The centering lens 75 isdisposed at the bottom portion 19 of the unit assembling portion 17.

The pressing plate 76 has a light transmission hole 76 a formed in theportion other than the periphery. A positioning hole 76 b and apositioning groove 76 c, spaced apart from each other in the right-leftdirection, are formed at the periphery of the pressing plate 76. Aplurality of pressing protrusions 76 d, 76 d, . . . that press theflange portion 75 b of the centering lens 75 from below are provided onthe upper surface of the pressing plate 76.

The packing 77 is made of, for example, a rubber material and has atransmission hole 77 a formed in the portion other than the periphery.Annular upper and lower pushing portions 77 b and 77 c protruding upwardand downward respectively are provided at the opening edges of thetransmission hole 77 a in the packing 77.

The imaging module 78 includes a base plate 79, an imaging device 80assembled to the base plate 79, and a glass plate 81 that covers theimaging device 80 from above.

Holes to be held 79 a, 79 a, spaced apart from each other in theright-left direction, are formed at the periphery of the base plate 79.Screw insertion holes 79 b, 79 b, spaced apart from each other in theright-left direction, are formed at the periphery of the base plate 79.The base plate 79 has a transmission hole 79 c for transmitting imagecapturing light formed in the portion other than the periphery.

The imaging device 80 is attached onto the lower side of the base plate79 and blocks the transmission hole 79 c.

The glass plate 81 is a member that protects the imaging device 80 andprevents dust from being deposited on the imaging device 80. The glassplate 81 is attached onto the upper side of the base plate 79 and blocksthe transmission hole 79 c. Therefore, the upper surface of the glassplate 81 is located at a level higher than the upper surface of the baseplate 79.

As shown in FIG. 37, the imaging unit 74 is attached to the unitassembling portion 17 in the following manner: The centering lens 75 isdisposed at the bottom portion 19. The attachment pins 19 b, 19 bprotruding from the bottom portion 19 are inserted into the positioninghole 76 b and the positioning groove 76 c in the pressing plate 76, sothat the pressing plate 76 is disposed under the centering lens 75. Theholding pins 20 a, 20 a provided at the peripheral side portion 20 ofthe unit assembling portion 17 are inserted into the holes to be held 79a, 79 a in the imaging module 78, so that the imaging module 78 isdisposed under the packing 77. The packing 77 is disposed under thepressing plate 76. Attachment screws 82, 82 inserted into the screwinsertion holes 79 b, 79 b in the imaging module 78 (see FIGS. 35 and36) engage threaded holes 20 b, 20 b formed in the peripheral sideportion 20.

With the imaging unit 74 disposed in the unit assembling portion 17, asshown in FIG. 37, the flange portion 75 b of the centering lens 75 ispressed by the pressing protrusions 76 d, 76 d, . . . of the pressingplate 76 from below. The upper pushing portion 77 b of the packing 77 ispressed against the lower surface of the pressing plate 76 from belowand elastically deformed. The glass plate 81 in the imaging module 78 ispressed against the lower pushing portion 77 c of the packing 77 frombelow, so that the lower pushing portion 77 c is elastically deformed.In this state, the centering lens 75 is pressed against the bottomportion 19 of the unit assembling portion 17 by the glass plate 81 inthe imaging module 78 from below via the pressing plate 76 and thepacking 77, and the centering lens 75 pressed from below can move in anarbitrary direction in a plane perpendicular to the optical axis.

A circuit substrate 83 is attached to the imaging module 78 from below.

With the imaging unit 74 disposed in the unit assembling portion 17 asdescribed above, the centering lens 75 is centered. The centeringoperation is carried out to balance the change in spatial frequency ofthe entire optical system (MTF) across the range from a wide-angle endto a telescopic end, the spatial frequency varying in accordance withthe position of the second movable unit 53 when it moves between thewide-angle end and the telescopic end.

The centering operation is carried out, as shown in FIG. 38, byinserting adjustment jigs 100, 100 that hold the centering lens 75through the working holes 20 c, 20 c formed in the peripheral sideportion 20 so as to hold the centering lens 75, and moving theadjustment jigs 100, 100 while detecting the spatial frequency of theentire optical system during the movement of the second movable unit 53between the wide-angle end and the telescopic end. The position of thecentering lens 75 is thus adjusted. The centering operation is carriedout as described above with the centering lens 75 pressed against thebottom portion 19 of the unit assembling portion 17 by the glass plate81 in the imaging module 78 via the pressing plate 76 and the packing77.

When the positional adjustment of the centering lens 75 is completed,that is, the centering operation is completed, an adhesive is applied tothe periphery of the flange portion 75 b of the centering lens 75 tosecure the centering lens 75 to the bottom portion 19 of the unitassembling portion 17. After the adhesive has been applied, sealingmembers 84, 84 that block the working holes 20 c, 20 c are glued ontothe outer surface of the lower half portion 11 in order to prevent dustfrom entering the working holes 20 c, 20 c in the unit assemblingportion 17 (see FIG. 5).

Securing the centering lens 75 by applying an adhesive is carried out,for example, by inserting adhesive applying nozzles (not shown) throughthe working holes 20 c, 20 c in the unit assembling portion 17,applying, for example, an UV curable adhesive, and irradiating theapplied adhesive with UV light to harden the adhesive.

As described above, securing the centering lens 75 to the unitassembling portion 17 after the position of the centering lens 75 hasbeen adjusted can prevent the position of the centering lens 75 fromshifting and ensure excellent optical characteristics of the centeringlens 75 even when an impact force is applied to the centering lens 75and the unit assembling portion 17, for example, when the imagingapparatus 1 falls.

Securing the centering lens 75 to the unit assembling portion 17 canalso prevent the position of the centering lens 75 from shifting andensure excellent optical characteristics of the centering lens 75 evenwhen the packing 77 is degraded, for example, due to aging.

Further, since the working holes 20 c, 20 c in the unit assemblingportion 17 can also be used as working holes through which the adhesiveapplying nozzles are inserted, it is not necessary to form dedicatedholes for inserting the adhesive applying nozzles into the unitassembling portion 17.

FIG. 39 shows graphs illustrating the relationship between the loadapplied to the packing 77 (load from below) and the amount ofdeformation of the packing 77. FIG. 39 shows that the force for movingthe centering lens 75 in the direction perpendicular to the optical axismay be smaller than the load applied to the packing 77.

As described above, in the lens barrel 8, the centering operation iscarried out by providing the imaging unit 74 including the centeringlens 75 that is pressed against the bottom portion 19 of the unitassembling portion 17 and adjusted in terms of position with respect tothe optical axis, the pressing plate 76 that presses the centering lens75, the packing 77 disposed on the opposite side of the pressing plate76 to the centering lens 75 and pressed against the pressing plate 76,and the imaging module 78 disposed on the opposite side of the packing77 to the pressing plate 76 and pressing the packing 77 against thepressing plate 76, and forming the working holes 20 c, 20 c, throughwhich the adjustment jigs 100, 100 for adjusting the position of thecentering lens 75 with respect to the optical axis, in the peripheralside portion 20 of the unit assembling portion 17.

Therefore, part of the imaging unit 74 is used as a mechanism forpressing the centering lens 75 to carry out the centering operationinstead of independently disposing the imaging unit 74 and a mechanismfor pressing the centering lens 75 spaced apart from each other. Theassembling space in the optical axis direction can be reducedaccordingly. The size of the lens barrel 8 can thus be reduced and thecentering lens 75 can be readily centered at the same time.

Further, the light transmission hole 76 a in the pressing plate 76 canbe used as a diaphragm opening that limits the amount of image capturinglight incident on the imaging device 80. Using the light transmissionhole 76 a as a diaphragm opening can prevent unwanted light among theincident image capturing light from being incident on the imaging device80. It is thus possible to prevent so-called ghosts, which are lightrings and balls, from being generated in an image due to repetitivelight reflection when unnecessarily intense light is incident.

Further, since the packing 77 is made of a rubber material, compressingthe packing 77 allows the centering lens 75 to be pressed against thebottom portion 19 of the unit assembling portion 17. It is thus possibleto absorb variation in the distance between the lower surface of thepressing plate 76 and the upper surface of the glass plate 81 and pressthe centering lens 75 at an appropriate pressure.

Moreover, since the glass plate 81 provided to protest the imagingdevice 80 and prevent dust from being deposited on the imaging device 80is used to press the centering lens 75 via the pressing plate 76 and thepacking 77, the number of parts can be reduced.

In addition, since the flange portion 75 b of the centering lens 75 ispressed by a plurality of pressing protrusions 76 d, 76 d, . . . of thepressing plate 76, the centering lens 75 is pressed at a plurality oflocations on the periphery of the lens portion 75 a. Therefore, thepressing force against the bottom portion 19 is distributed thereacrossto ensure stable pressing.

Since the peripheral portion of the glass plate 81 is in tight contactwith the lower pushing portion 77 c of the packing 77, the packing 77can prevent dust from being deposited on the portion of the glass plate81 through which image capturing light passes and prevent black dotsfrom being imaged or smears and the like from being produced in an imagedue to deposited dust.

A flexible printed wiring board 85 is provided to energize necessaryportions in the lens barrel 8, and most part of the flexible printedwiring board 85 is glued and attached to the outer surface of the outerenclosure 9 (see FIGS. 5 and 40). The flexible printed wiring board 85energizes the first drive motor 27, the second drive motor 33, theposition detection sensors 73, 73, and other electric components.

Since the flexible printed wiring board 85, excluding part thereof, isglued to the outer surface of the outer enclosure 9, almost no dedicatedassembling space for the flexible printed wiring board 85 is necessary,and hence the size of the lens barrel 8 can be reduced.

In the outer enclosure 9, a flexible printed wiring board 86 forenergizing the joining member 55 provided as a shutter or diaphragmdevice is extended from the joining member 55 (see FIGS. 25 and 26). Theflexible printed wiring board 86 is formed into an elongated shape, andone end of the flexible printed wiring board 86 is extended out of theouter enclosure 9 and connected to the flexible printed wiring board 85.

The flexible printed wiring board 86 is disposed along the first guideshaft 40, and bent when the second movable unit 53 moves in the up-downdirection.

Since the flexible printed wiring board 86 has an elongated shape and isdisposed along the first guide shaft 40, the assembling space for theflexible printed wiring board 86 is advantageously very small, wherebythe size of the lens barrel 8 can be reduced.

In the thus configured lens barrel 8, operating the imaging key 4 fdisposed on the first housing 2 activates the drive mode in which imagescan be captured, and the user is ready to image a subject.

When a subject is imaged, image capturing light is introduced as animage capturing signal through the objective lens 37 in the optical axisdirection P1 (see FIG. 19). The image capturing light introduced throughthe objective lens 37 is bent off the prism 38 by 90 degrees along theoptical axis P2 perpendicular to the optical axis P1 (see FIG. 19) andincident on the imaging device 80 in the imaging module 78 through thefirst fixed lens 39, the focus lens 44 in the first movable unit 43, thezoom lens 56 in the second movable unit 53, and the centering lens 75provided as the second fixed lens. The image capturing light as an imagecapturing signal incident on the imaging device 80 is photoelectricallyconverted into an image signal in the imaging device 80.

In this process, the first drive motor 27 is driven to rotate the firstlead screw 26 so as to move the first nut member 28, and the firstmovable unit 43 is guided along the first guide shaft 40 and the guidingshaft 42 and moved in the optical axis direction P2 for auto focusing.

When the user initiates zooming operation, the second drive motor 33 isdriven to rotate the second lead screw 32 so as to move the second nutmember 34, and the second movable unit 53 is guided along the secondguide shaft 41 and the guiding shaft 42 and moved in the optical axisdirection P2 for zooming. The zooming operation is carried out by movingthe second movable unit 53 in the optical axis direction P2 between thewide-angle end (see FIG. 41) and the telescopic end (see FIG. 42).

The second movable unit 53, when moved upward, approaches the telescopicend, whereas the second movable unit 53, when moved downward, approachesthe wide-angle end. The area over which the second movable unit 53 moveson the telescopic end side overlaps with the area over which the firstmovable unit 43 moves in the focusing operation. However, the firstmovable unit 43 and the second movable unit 53 are controlled not tointerfere with each other when they are in motion.

As described above, in the lens barrel 8, the first lead screw 26 andthe second lead screw 32 are disposed in such a way that they are spacedapart in the up-down direction, and part of the area over which thefirst movable unit 43 moves overlaps with part of the area over whichthe second movable unit 53 moves.

Therefore, disposing the first lead screw 26 and the second lead screw32 in such a way that they are spaced apart in the up-down directionprevents the first nut member 28 and the second nut member 34 frominterfering with each other, and setting part of the area over which thefirst movable unit 43 moves to overlap with part of the area over whichthe second movable unit 53 moves allows reduction in size of the lensbarrel 8 in the optical axis direction P2.

In the thus configured lens barrel 8, the first nut member 28 and secondnut member 34, when made of a rigid material, have higher resistance toimpact, whereby any of the teeth of the first nut member 28 and thesecond nut member 34 will unlikely be chipped or scraped by the firstlead screw 26 and the second lead screw 32. It is thus possible toimprove reliability of the operation of the first movable unit 43 andthe second movable unit 53 and the size of the lens barrel 8 is reducedin the optical axis direction P2 at the same time.

Further, in the lens barrel 8, as described above, since the centralaxis M1 of the first lead screw 26 is aligned with the central axis M2of the second lead screw 32, the first drive unit 23 and the seconddrive unit 24 that form the drive system are disposed in the left endportion in a compact manner, as shown in FIGS. 41 and 42, and the firstmovable unit 43, the second movable unit 53, and other components thatform the optical system are disposed on the right side in a compactmanner.

Therefore, the assembling space in the outer enclosure 9 can beeffectively used, and the size of the lens barrel 8 can be reducedaccordingly.

Further, in the lens barrel 8, since the guiding shaft 42 for guidancein the optical axis direction is shared by the first movable unit 43 andthe second movable unit 53 as described above, reduction in the numberof parts and reduction in the assembling space can contribute to sizereduction.

The overall configuration of the imaging apparatus 1 will be describedbelow with reference to the block diagram shown in FIG. 43.

The imaging apparatus 1 includes a CPU (Central Processing Unit) 87, andthe CPU 87 controls the overall operation of the imaging apparatus 1.Specifically, the CPU 87 allocates a control program stored in a ROM(Read Only Memory) 88 onto a RAM (Random Access Memory) 89 and controlsthe operation of the imaging apparatus 1 via a bus 90.

A camera controller 91 has a capability of controlling the lens barrel 8to capture still images and video images. The camera controller 91, forexample, compresses an image signal (image information) formed byphotoelectric conversion performed in the imaging device 80 using JPEG(Joint Photographic Experts Group), MPEG (Moving Picture Experts Group),or other formats and sends the compressed data to the bus 90. The imageinformation sent over the bus 90 is temporality stored in the RAM 89,and outputted to a memory card interface 92 and stored in a memory card93 through the memory card interface 92, or displayed on the display 6via a display controller 94 as required.

When an image is captured, an audio signal (audio information) inputtedfrom the microphone 5 is temporarily stored in the RAM 89 or stored inthe memory card 93 via an audio codec 95 along with the imageinformation. The audio information is outputted from the loudspeaker 7via the audio codec 95 concurrently with the image information displayedon the display 6.

The image information and the audio information described above areoutputted to an infrared interface 96 as required, outputted by theinfrared interface 96 through an infrared communication unit 97, andtransmitted to an external apparatus equipped with an infraredcommunication unit, such as a mobile phone, a personal computer, and aPDA (Personal Digital Assistant). When video images or a still image isdisplayed on the display 6 based on the image information stored in theRAM 89 or the memory card 93, the camera controller 91 decodes oruncompresses a file stored in the RAM 89 or the memory card 93, and theresultant image data are sent to the display controller 94 via the bus90.

A communication controller 98 sends and receives radio waves to and froma base station via an antenna 99. In a calling mode, received audioinformation is processed, and the processed audio information isoutputted to the loudspeaker 7 via the audio codec 95. Further, audioinformation inputted from the microphone 5 is received via the audiocodec 95, undergoes predetermined processing, and is transmitted.

The specific shapes and structures of the components shown in the bestmode for carrying out the invention described above are only an examplefor embodying the invention. The technical extent of the inventionshould not be construed in a limited sense by these specific shapes andstructures.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

1. A lens barrel comprising: a plurality of lenses disposed in an outerenclosure; and an imaging device that converts image light introduced asan image capturing signal through the plurality of lenses into an imagesignal, wherein the outer enclosure has a unit assembling portion inwhich an imaging unit is disposed, the unit assembling portion having abottom portion and a peripheral side portion protruding from theperipheral edge of the bottom portion, the imaging unit includes acentering lens disposed in the bottom portion of the unit assemblingportion in such a way that the centering lens is pressed against thebottom portion, the centering lens to be adjusted in terms of positionwith respect to the optical axis, a pressing plate that presses thecentering lens from the side opposite the bottom portion, the pressingplate having a light transmission hole through which the image capturinglight passes and impinges on the imaging device, a packing disposed onthe opposite side of the pressing plate to the centering lens andpressed against the pressing plate, the packing having a transmissionhole through which the image capturing light passes and impinges on theimaging device, and an imaging module disposed on the opposite side ofthe packing to the pressing plate and pressing the packing against thepressing plate, the imaging module having the imaging device, and aworking hole through which an adjustment jig is inserted is formed inthe peripheral side portion of the unit assembling portion, theadjustment jig used to adjust the position of the centering lens pressedagainst the bottom portion with respect to the optical axis.
 2. The lensbarrel according to claim 1, wherein the centering lens is glued andsecured to the unit assembling portion after the position of thecentering lens has been adjusted with respect to the optical axis, anadhesive applying nozzle is inserted through the working hole in theunit assembling portion to apply an adhesive in the operation of gluingthe centering lens, and the centering lens is secured in the unitassembling portion by irradiating the applied adhesive with UV light. 3.The lens barrel according to claim 1, wherein the light transmissionhole in the pressing plate is used as a diaphragm opening that limitsthe amount of the image capturing light that impinges on the imagingdevice.
 4. The lens barrel according to claim 1, wherein the packing ismade of a rubber material.
 5. The lens barrel according to claim 1,wherein a flat-plate-shaped glass plate is provided in the imagingmodule, the glass plate pressed against the packing to protect theimaging device.
 6. The lens barrel according to claim 1, wherein thecentering lens includes a lens portion and a flat-plate-shaped flangeportion provided at the periphery of the lens portion, and a pluralityof pressing protrusions are provided on the pressing plate, the pressingprotrusions pressing the flange portion of the centering lens.
 7. Animaging apparatus comprising a lens barrel incorporated in a housing,the lens barrel including a plurality of lenses disposed in an outerenclosure, and an imaging device that converts image capturing lightintroduced as an image capturing signal through the plurality of lensesinto an image signal, wherein the outer enclosure has a unit assemblingportion in which an imaging unit is disposed, the unit assemblingportion having a bottom portion and a peripheral side portion protrudingfrom the peripheral edge of the bottom portion, the imaging unitincludes a centering lens disposed in the bottom portion of the unitassembling portion in such a way that the centering lens is pressedagainst the bottom portion, the centering lens to be adjusted in termsof position with respect to the optical axis, a pressing plate thatpresses the centering lens from the side opposite the bottom portion,the pressing plate having a light transmission hole through which theimage capturing light passes and impinges on the imaging device, apacking disposed on the opposite side of the pressing plate to thecentering lens and pressed against the pressing plate, the packinghaving a transmission hole through which the image capturing lightpasses and impinges on the imaging device, and an imaging moduledisposed on the opposite side of the packing to the pressing plate andpressing the packing against the pressing plate, the imaging modulehaving the imaging device, and a working hole through which anadjustment jig is inserted is formed in the peripheral side portion ofthe unit assembling portion, the adjustment jig used to adjust theposition of the centering lens pressed against the bottom portion withrespect to the optical axis.